1. Field of the Invention:
The invention relates to means for opening and closing sliding doors, particularly sliding doors of railway house cars.
2. The Prior Art:
Railway car door moving structures have frequently utilized racks mounted on the car side with manually actuating pinions journaled on the car door structure for moving the door lengthwise of the car between closed and open positions. In some instances, the rack has been mounted on the car side wall at a level substantially higher than the door track while in other instances, as exemplified by A. E. Ashleman U.S. Pat. No. 1,575,086 and two Canadian patents, George Tuman Pat. No. 159,599 and F. G. Evans Pat. No. 282,778, the racks have been mounted on the door track. In the Ashleman and Tuman patents, the rack-engaging pinions were operated directly by an operating handle affixed to the pinion shaft on the bottom of the door substantially at the center of the door, while in Evans one of the door-mounting rollers is formed with teeth on its circumference and functions as the rack-engaging pinion as well as the door supporting roller. In all of these patented structures, it would be difficult to utilize the rack and pinion operating means to open or close the door when the car was positioned beside a car floor level loading platform such as is commonly provided at freight houses and at shippers' loading docks, requiring a person operating a door with such arrangements to kneel on the platform adjacent the door and if possible extend his arm and hand into the narrow space between the platform and the car side, at the same time crawling along the platform as the door moves between closed and open positions.